hello. this is bbc news. i'm rich preston. our top stories: explosion as the pentagon says ukrainian soldiers are going on the offensive to reclaim ground, we report on the battle for a key town in the south of ukraine where russian forces are being pushed back. this war is only a few weeks old and the russians will almost certainly be back with more soldiers and a lot more firepower. fleeing the besieged city of mariupol: survivors tell of children starving to death. a prominent kremlin critic gets another jail sentence: the us says it's part of the crackdown on dissent to hide the war in ukraine.

and the women's world number one, ash barty, says she's retiring from tennis. hello and welcome to the programme. very good to have your company. the pentagon says ukrainian soldiers are successfully reversing battlefield momentum against invading russian forces to reclaim ground in some parts of the country. but the intense bombardment of the southern port city of mariupol shows no signs of abating with the ukrainian president saying damage is so bad it no longer exists. a spokesman for the us defense department says there were some optimistic signs in other areas of the south. ukrainians are going a bit more

on the fence now. they have been defending very smartly, very creatively in places that they believe are the right places to defend, and we have seen them now in places, particularly in the south, they have tried to regain territory. again, we don't have great fidelity of tactical movements, but we have seen them make these efforts, and is not... the ukrainians themselves several days ago that they were planning on counter—attacks, so i think we have seen indications that they are moving in that direction. reports are now emerging of local citizens and ukrainian soldiers in the southern town of voznesensk, with a population ofjust 35,000, destroying a column of russian tanks and pushing back russian troops who attacked the town. from there, our correspondent andrew harding sent this report.

in war, a single bridge can sometimes make all the difference. a bridge and a town determined to keep it from the enemy. and that's what happened here in voznesensk, a quiet farming community that stood its ground. security cameras captured the moment russian tanks roared into town, determined to seize the bridge, and beyond it, a clear road across southern ukraine. but the locals were already setting a trap. all hands on deck. blocking off roads, guiding the russians into an ambush. gunfire a local shopkeeper, alexander, filmed himself on the front lines. "you little beauties!" he shouts.

"it was a colossal effort by the whole town," he says. "we used hunting rifles, people threw bricks, "old women loaded sandbags, "the russians didn't know where to look. "i've never seen the community come together like that." as the invaders approached the bridge, the locals blew it up — at which point these british anti—tank weapons played a decisive role. the ukrainians destroyed almost every russian vehicle, denying them the chance to seize the town and to rebuild the bridge. tank tracks still mark svetlana nikolajevna's garden. her outhouse took a direct hit. she says the russians took two ukrainian soldiers prisoner in there, and she feared they were going to kill them, but then the battle got out of hand.

that's the blood of russian soldiers who were sheltering in her house. while she hid in a cellar, her cottage became a russian field hospital. translation: they left at night in such a hurry. | they left almost everything behind. theyjust took their dead and wounded. it may be russia's heaviest defeat so far, their troops retreating far to the east. this town, this community achieved something remarkable here, but we need to put it in perspective. this war is only a few weeks old, and the russians will almost certainly be back with more soldiers and a lot more firepower. not surprisingly, the town hall is crowded with people wanting help getting out of voznesensk. 0thers go straight to the 32—year—old mayor. he's well guarded these days, brimming with confidence, but realistic about what lies ahead. "we know we can't win here

"without more anti—tank weapons," says yevheni velichko. "we're grateful for western supplies, but we need more. "we know the russians will be back." back for the bridge and back for the town that stood its ground. andrew harding, bbc news, in voznesensk, southern ukraine. while russia has continued its bombardment of several ukrainian cities, advances have ground to a halt in many areas with ukrainian forces also launching counter—attacks. matthew sussex is a senior fellow at the australian defence college, specialising in russian security policy. hejoins me from canberra. good afternoon to you in australia. at the start of the invasion, when you looked at the numbers, russia is a bigger country, more money on guns, more troops, it seemed like a foregone conclusion. but that

has not been the case. what is it that stalled this russian advance? it it that stalled this russian advance?— advance? it has been a combination _ advance? it has been a combination of - advance? it has been a combination of things. | advance? it has been a | combination of things. i advance? it has been a - combination of things. i think for starters, the russian armed forces have overestimated their own ability to advance very swiftly into ukraine. the plan that they went with was a sort of lightning strike against gear. and other major population centres —— kyiv. they got very bogged down very quickly. there was a miscalculation. the second thing of course is the phenomenal resistance of the ukrainians. most events policy planners would, in the west, would have thought that the ukrainians would capitulate very, very quickly in the face of the russian onslaught, but that of course hasn't happened either thanks very much to their resistance. so i think

those two things are going on. and then there are the other things you hear, things like low troop morale on the russian side, very bad logistics, no real co—ordination, no real sense of an object. so this is what has led us to this place. unfortunately, russia is reverting to what it tends to do in urban offensive, which is to fire heavy artillery and drop bombs on population centres. i drop bombs on population centres. . , drop bombs on population centres. ., , ., ., ., , ., centres. i was going to ask you about that, _ centres. i was going to ask you about that, because _ centres. i was going to ask you about that, because if - about that, because if this ukrainian resistance has surprise russian forces and unconventional tactics haven't worked, what are the risks that russia will resort to more and more extreme measures as they have done elsewhere in the past? it have done elsewhere in the -ast? , have done elsewhere in the ast? , . ., , , past? it is certainly very concerning. _ past? it is certainly very concerning. one - past? it is certainly very concerning. one of- past? it is certainly very concerning. one of the l past? it is certainly very - concerning. one of the things that the kremlin likes to do is to press ignore what its intentions might be or what its options, what options are being considered. some of those have come in the form of veiled

references, and overt references, and overt references to ukrainian nuclear weapons programmes, dirty bombs, chemicalweapons weapons programmes, dirty bombs, chemical weapons and so forth. so there is a concern that one of these will be used as a pretext, a false flag by the kremlin to then justify an increase in russian retaliation.- increase in russian retaliation. , ., , . ., increase in russian retaliation. , retaliation. dmitri pascoe said in an interview _ retaliation. dmitri pascoe said in an interview that _ retaliation. dmitri pascoe said in an interview that russia - in an interview that russia might be forced to use its nuclear weapons if it faced an existential crisis. what is an existential crisis. what is an existential threat to russia? that is a $60 million question, isn't it? because apparently ukraine resented an existential threat to the russian federation, which is extraordinary, given that it has six thousand, 6500 nuclear weapons. more than capable of securing itself, its physical integrity against ukraine and nato for that matter. so i

think the only logical conclusion is that an existential crisis against the russian state is a crisis and a threat to the russian government, not the state per se, and the rule of vladimir putin, which tells us i think a fair bit about where the genesis of this conflict has really come from. we genesis of this conflict has really come from.- genesis of this conflict has really come from. we will have to leave it _ really come from. we will have to leave it there. _ really come from. we will have to leave it there. matthew - to leave it there. matthew sussex from the australian defence college, and you very much for making the time for us. the southern port city of mariupol is a key strategic target for russia. many have fled, but around 300,000 people are believed to be trapped there with food and water running out. 0ur correspondent wyre davies sent this report from zaporizhzhia where some people from mariupol have managed to flee. after 170 miles, mined roads and 15 russian army checkpoints — freedom. their ordeal is by no means over, but for these families who have escaped from mariupol

in a motley convoy of bomb—damaged vehicles, the last month has been as close to hell as any human should ever get. it was bombing every ten, five minutes and we haven't any central heating, gas, electricity, food or water, nothing. before leaving, katya grabbed her obstinate dog jesse, but this isn't the first time she's fled war. i passed through war in 2014. i'm from donetsk. but it was light variant, really. and now, it's my second war, but it is harder. this van, filled with 25 people, also made it through today. all occupants of the same bunker in mariupol escaping together — from ages 2 to 75. 0vercome with emotion, �*babushka', or grandmother,

anna, says, "it's all too much for me at my age." some of those arriving today gave us videos, a snapshot of the nightmare in which they've been living and the perils of their journey out. around 300,000 people are still thought to be trapped inside the besieged city, much of which has been destroyed by the russian bombardment. from the sky in particular, russia is causing real damage to mariupol�*s civilian and industrial infrastructure. it was a bombardment that almost took the life of two—month—old volodymyr. when a shell landed near their apartment, his father instinctively threw himself over the baby. dad alexei was hit by shrapnel and glass. his son, born only a month before the war, bears no injuries. "after that we lived in the shelter, "cooking with wood and just trying to survive," says alexei.

ukrainians have their differences, but the war has brought people together in adversity. volunteers provide anything those escaping mariupol need for their onward journeys, knowing full well that their town could be next. wyre davies, bbc news, zaporizhzhia. stay with us on bbc world news. still to come, leaving with pride: why the women's world number one, ash barty, says it's time to hang up her racquet. applause i'm so proud of both of you. let there be no more wars or bloodshed between arabs and israelis.

with great regret, _ the committee have decided that south africa be excluded . from the 1970 competition. singing in own language streaking across the sky, the white—hot wreckage from mir drew gasps from onlookers on fiji. this is bbc world news. the latest headlines: ukraine's president says there's a chance of surviving the war as his military stops the russian advance on some key targets.

in russia, the country's most prominent opposition figure, alexei navalny, has been given a nine—year prison sentence, after being found guilty of fraud and contempt of court, charges which are widely considered to be fabricated. mr navalny is already in prison. 0ur russia editor steve rosenberg has more details. navalny the images are grainy, but the meaning was clear. kremlin critic alexei navalny, already a prisoner, was about to receive anotherjail term. his prison colony had been turned into a courtroom. his supporters call it a show trial. he was sentenced to nine years, maximum security, for fraud. this was mr navalnyjust over a year ago, russia's most prominent opposition figure, detained when he flew into moscow. his arrest and imprisonment sparked nationwide protests. protester yells.

but what followed was a kremlin crackdown. the result? more repression, less freedom. so much has happened here in the last year. the russian opposition has been crushed, kremlin critics have been silenced. this feels like a very different russia. and that feeling is all the stronger after president putin's decision to send his troops into ukraine. the kremlin calls what it's doing in ukraine a �*special military operation�*. it demands that everyone do the same. the freedom of speech is non—existent. this is the horrible war that we are not even allowed to call the war, because here it is called a �*special operation�*. and people that come onto the streets with a banner "no war" are detained.

russian mp maria butina thinks that in times of trouble, russians should support the motherland. as for alexei navalny? he cheated on the government. he cheated on certain businesses. it is widely seen as politically motivated. it is not politically motivated. absolutely not. so there are no political prisoners in russia? there are no political prisoners in russia. not a single one? not a single one, absolutely. and that is precisely the picture that the kremlin paints for the russian people, hoping they�*ll believe that there�*s no repression here, no war, no problem. steve rosenberg, bbc news, moscow. for more on this, i�*ve been speaking to maria snegovaya, visiting fellow at george washington university, and senior fellow at the center for a new american security in washington. she gave me her reaction to the navalny sentencing.

the prosecutor actually asked for 13 years of imprisonment, so it in some unparallel world, you know, it is a decrease in sentence. unfortunately, russia�*s quickly sinking into darkness with an opposition to destroy, and of course the key 0pposition leaderjailed, essentially follow. we all understand that alexei navalny will stay injailfor as long as putin is alive. as of now, he is to be released in 2031, as horrible as it sounds. the kremlin has tightened rules on what the media can report in russia. what are russians being told about alexei navalny�*s sentence, and how much of what is going on in ukraine played into this? unfortunately, the ukraine situation has distracted this major process, major trial, the public attention from this trial, and unfortunately — it is very well—deserved that ukraine gets all of the attention but all of these

other horrible things unravelling and russia therefore are not noticed by many, including the domestic audience. especially now there is a huge breakdown on all independent media. we practically have no independent media, even on internet in russia at all. and now, navalny is seen as somebody who allegedly committed another crime and will be placed in a special high security colony, where any public access or even his lawyers�* access will be extremely complicated. we will hear less and less from navalny and his life is threatened. the kremlin has already tried to kill him. of course, on tv, on state—owned control tv, people do not hear anything about this. the very best of what they hear is that alexei navalny as a traitor. you know, traitors should be eliminated, particularly during these times of crisis when, as putin has said, they need unity and defence. you mention the high

security colony. he has been sentenced to nine years of strict regime. what does that mean for him? unfortunately, it means way less public access, stricter conditions under which he will be held, less freedom, essentially inside of the colony. most importantly, the public lawyers, journalists will have very limited access to him. every week at this time we take a look at the climate crisis, bringing you stories with big implications for our planet. this week, after a month of war in ukraine, we focus on energy security — how the world can replace its so—called addiction to russian coal, oil and gas. many countries are urgently looking to strike fossil fuel deals elsewhere or ramp up domestic production. just this

week un secretary general anthony gutierez condemned the move as madness, saying it would end any hope of limiting global warming to 1.5 degrees this century. for that to happen the carbon footprint needs to be hard this decade, as things stand emissions are due to rise by for %. —— 15%. so can we keep the lights on and limit price rises without hurtling towards a climate catastrophe? and are renewables ready to fill the energy gap? here to help us answer these questions is svitlana romanko — a ukrainian climate activist, environmental lawyer and founder of stand with ukraine — a campaign calling for a ban on russian oil and gas, and an end to fossil fuel funding globally. russia funding globally. is a huge it reserves in the russia is a huge it reserves in the world. among the top ten when it comes at the same time

we western nations, surely that means if we not buying russian oil and that is a win absolutely, thank you for having me here today. allowing me to for renewables _ having me here today. allowing me to for renewables they - having me here today. allowing me to for renewables they have on the global political landscape and local first of all, i don�*t responding to this war by doubling down the things that have led us to this crisis moment with the ukrainian will in the climate crisis i want hero to i do understand with

colleagues which is as you understand, as foreboding of all trade and that feed the putin war machine that right now destroys my home country, and our cities and actually my city where i also live has been bombarded for a few times, it�*s in the western part of ukraine. nowhere is safe, and the transition plans of my country have been seriously damaged. we have been seriously damaged. we have seven cities of ukraine declared four centres of renewable energy transition and i was part of this campaign at this time. we can see global sentiment has turned. it should stop at all russian assets and fossil fuels, stop at all russian assets and fossilfuels, the stop at all russian assets and fossil fuels, the energy system is global and its fossil fuels

that are toxic, as long as we have fossil fuels we will empower regimes, initiating conflict for that purpose as you said some governments have been moved, president biden has announced a full embargo on russian oil and gas, a few days ago, our president endorsed this political move, and the announcement, going to the heart of putin�*s firmaments. he was the biggest ally of ukraine, fossilfuel and gas ukraine, fossil fuel and gas were ukraine, fossilfuel and gas were from russia as well. we will need _ were from russia as well. we will need to — were from russia as well. we will need to leave it there, we are out of time, thank you very much for being with us.

tennis — and the world number one, ash barty, has announced she�*s retiring from the game. in a surprise announcement on social media she said she was leaving the sport �*proud and fulfilled�*. the 25—year—old won three grand slam singles titles, including the australian open injanuary. this is how she made the announcement. i'll i�*ll be retiring from tennis. and it�*s the first time i�*ve actually said that out loud, and, yes it�*s hard to say, but i�*m so happy, and i�*m so ready, and ijust know at i�*m so happy, and i�*m so ready, and i just know at the i�*m so happy, and i�*m so ready, and ijust know at the moment, in my heart, for me as a person this is right. and i know i�*ve done this before, but in a very different feeling. and i�*m so grateful to everything that tennis has given me, it�*s given me all of my dreams possible, but i know that the time is right now for me to step away and chase other dreams. and, year, to put the rackets down.

that�*s it from us for now, much more on the bbc website. you can reach me on twitter — i�*m @ richpreston. we�*ll see you next time. hello there. at this time of year, warm days are often followed by decidedly chilly nights. and tuesday was certainly a warm day, with temperatures in northwest wales getting close to 21 degrees, the warmest day of the year so far. plenty of other places not too far behind. but as soon as the sun went down, the temperatures followed. it has been turning quite chilly out there. high pressure still close by on wednesday. it stays mostly dry, but with those clear skies overhead, quite a chilly start to the morning, with temperatures down around freezing, below freezing in a few places. one or two early fog patches around as well. they should tend to lift and clear by the middle part of the morning. and then it is another beautiful spring day, with lengthy spells of sunshine. the vast majority will stay dry. there�*s just a small chance of one

or two showers popping up in northeast scotland and maybe across eastern counties of england. not as breezy as it was on tuesday across western areas and every bit as warm. top temperatures between 16 and 20, maybe 21 degrees. but as we head through wednesday night, again, the sun goes down, the orange colours drain away from the map, replaced by blues and greens, with temperatures again dropping down to around freezing. those are the values for the towns and the cities. out in the countryside, i think there will be a touch of frost, and again potentially some fog patches on thursday morning. now, england and wales will once again have a mostly sunny day, with just the odd rogue shower. for scotland and northern ireland, expect more cloud creeping in from the northwest, with some spots of light rain and drizzle. top temperatures through thursday between 16 and 19 degrees in most places. now, for friday, again, the further north you are, there will be a bit more in the way of cloud. some rain for the northern isles. further south, more in the way of sunshine, a bit more of a breeze through the english channel at this stage, and temperatures maybe down just a fraction but still getting up to between 15 and 19 degrees.

and then we head into weekend, and some of that cloud in the north associated with a weak frontal system will try to work a little further southwards, but high pressure continues to hold firm, so despite that extra cloud and the greater chance of a bit of fog, it is going to stay fine and dry with some spells of sunshine. into next week, though, we develop a northerly wind. it�*ll start to feel quite a lot colder and there could even be some wintry showers.

this is bbc news. the latest headlines: ukraine says continued russian shelling is still stopping rescue workers reaching the theatre in mariupol which was targeted last wednesday. they say hundreds of people are trapped in the theatre�*s bomb shelter. there are reports that food and water shortages in the city mean that children are starving to death. ukraine says its troops have managed to stop russian soldiers advancing on the port city of 0desa. heavy fighting is continuing in many parts of the country. united nations head antonio guterres has appealed for an end to the war, warning it�*s becoming more unpredictable by the hour. the us has condemned what it called russia�*s orchestration of a sham trial

against the kremlin critic, alexei navalny.